TCP Subframe connectors...

I remember hearing something about TCP going out of business or changing ownership or something. I didn't want any hassles so I also went with the Global West tubular subs. I was impressed with the build quality and heftiness. Good luck.
 
All the TCP stuff will from now on be made by a place called Chris Alston's Chassisworks. Last I spoke to them they're still tooling up for production -- availability is spotty.

Just make your own. It's a bit of tubing and some gussets.